Pennsaid is expensive primarily because it uses a patented delivery system that generic versions of diclofenac don’t replicate, and insurance plans frequently refuse to cover it. A 112-gram pump bottle of Pennsaid 2% can cost over $2,400 at retail pharmacies without insurance, making it one of the priciest topical pain medications on the market.
What Makes Pennsaid Different From Other Diclofenac Products
Pennsaid contains diclofenac, the same anti-inflammatory drug found in over-the-counter Voltaren Gel. What you’re really paying for is the delivery vehicle. The original Pennsaid 1.5% formula uses 45.5% DMSO (dimethyl sulfoxide), a chemical that dramatically improves how well diclofenac passes through the skin. Diclofenac on its own is a fatty molecule that doesn’t penetrate skin easily. DMSO acts as a carrier, pulling the drug through skin layers that would otherwise block it. Studies show this DMSO-based vehicle delivers significantly more diclofenac into the tissue compared to water-based formulations without it.
The newer Pennsaid 2% formulation was designed as a convenience upgrade. It uses a metered-dose pump and a higher concentration, which means you apply it twice daily instead of the 40-drops-four-times-daily regimen required by the 1.5% solution. That reduced application schedule is a genuine practical benefit for people managing chronic knee osteoarthritis, but it also gave the manufacturer a new product to patent and price at a premium.
Limited Generic Competition Keeps Prices High
Generic versions of the older Pennsaid 1.5% solution do exist and cost significantly less. But the 2% pump formulation has faced a slower path to generic competition. The FDA confirmed in August 2024 that Pennsaid 2% was not withdrawn from the market for safety or effectiveness reasons, a determination that clears the way for generic manufacturers to submit applications referencing the brand product. Until generics actually reach pharmacy shelves, however, the brand version faces little price pressure.
This is a common pattern in pharmaceutical pricing. A manufacturer develops a modestly improved version of an existing drug (higher concentration, different dosing schedule, new delivery device), secures new patents on that version, and prices it as a brand-name product even though the active ingredient has been available for decades. Generic diclofenac gel at 1% is available over the counter for under $15. The leap to $2,400 for Pennsaid 2% reflects the cost of the proprietary formulation, not the drug itself.
Insurance Plans Often Won’t Cover It
Even with insurance, getting Pennsaid covered can be difficult. Most plans classify it as non-formulary or require prior authorization, meaning your doctor has to prove you’ve already tried and failed cheaper alternatives before the plan will pay. Those alternatives typically include oral NSAIDs like ibuprofen and naproxen, as well as generic topical options.
In one documented case from New York, an insurer denied coverage for Pennsaid for a patient with worsening bilateral knee osteoarthritis, even though she had already failed treatment with ibuprofen, naproxen, and another topical agent. The denial was eventually overturned on appeal, with the state ruling that oral NSAID alternatives were inappropriate because the patient needed to avoid gastrointestinal side effects. But that appeal process takes time and persistence, and many patients simply pay out of pocket or switch to a different product.
When insurers do cover Pennsaid, they typically place it on a high copay tier. Copays of $75 to $150 per fill are common even with coverage, which still makes it one of the more expensive prescriptions in a typical medicine cabinet.
Lower-Cost Alternatives Worth Knowing About
If you’re prescribed Pennsaid and can’t afford it, several options deliver the same active ingredient at a fraction of the price. Over-the-counter Voltaren Gel (1% diclofenac) is the most accessible. It requires four applications per day instead of two, and the formulation doesn’t include DMSO, so absorption may be somewhat lower. For many people with mild to moderate knee osteoarthritis, it works well enough.
Generic diclofenac sodium 1.5% topical solution is the prescription alternative that most closely mirrors the original Pennsaid formula. It contains the same DMSO-based vehicle and is typically available for $30 to $80, depending on your pharmacy. The tradeoff is the more cumbersome dosing: you apply 40 drops spread across four daily sessions rather than two quick pumps.
Manufacturer copay cards and patient assistance programs can also reduce costs for the brand product, though eligibility varies and these programs typically don’t apply if you’re on Medicare or Medicaid. Pharmacy discount tools like GoodRx sometimes bring the price of Pennsaid 2% down to around $260 for 112 grams, a steep discount from the full retail price but still far more expensive than generics.
Why the Price Gap Is So Large
The core issue is that Pennsaid 2% sits in an awkward market position. It’s a genuine improvement in convenience over the 1.5% generic, but diclofenac itself is a decades-old drug with no remaining exclusivity. The high price reflects patent protection on the specific 2% pump formulation, the cost of FDA clinical trials needed to prove the new dosing schedule works, and a market where the manufacturer faces little direct competition for that exact product configuration. Once generic versions of the 2% formulation reach the market, prices should drop substantially, following the same pattern seen when the 1.5% solution went generic. Until then, the price remains high because it legally can be.